3D Trajectory and Transmit Power Optimization for Blockage-Aware UAV Monitoring Systems

In this paper, we investigate a system in which an unmanned aerial vehicle (UAV) monitors multiple points of interest (POIs) and transmits collected data to a central monitoring unit (CMU) in an environment with blockages. In this system, the UAV needs to satisfy three necessary constraints during its flight. First, it must ensure a line-of-sight (LoS) condition with the POIs for accurate monitoring. Second, it must establish a LoS channel with the CMU for efficient information transmission. Lastly, the UAV must avoid blockages to perform its tasks stably without collisions. These constraints are generally non-convex sets, which are hard to solve. We replace these three constraints with linear inequalities using the separating hyperplane theorem and explain the principle. Based on successive convex approximation, the trajectory and transmit power of the UAV are optimized with the goal of maximizing the minimum rate during flight time. The simulation shows that the proposed method satisfies the constraints and outperforms existing methods.